排序方式： 共有30条查询结果，搜索用时 421 毫秒
1.
Random walk approach is used to develop a model for long-term prediction of water quality in shallow marine waters. The model allows one to simulate variations in hydrological situations, reactive solutes, interaction between solutes and liquid and solid boundaries. The model application is illustrated by calculations for Amur Bay. Calculations using the long-term prediction model has not found a stationary state in the pollution level. The velocities of seaward motion of pollution front and the rates of increase in the concentration of a nonreactive solute are given. 相似文献
2.
Andriy Gnyp 《Acta Geophysica》2009,57(2):330-345
Based on the results of application of correlation analysis to records of the 2005 Mukacheve group of recurrent events and
their subsequent relocation relative to the reference event of 7 July 2005, a conclusion has been drawn that all the events
had most likely occurred on the same rup-ture plane. Station terms have been estimated for seismic stations of the Transcarpathians,
accounting for variation of seismic velocities beneath their locations as compared to the travel time tables used in the study.
In methodical aspect, potentials and usefulness of correlation analysis of seismic records for a more detailed study of seismic
processes, tectonics and geodynamics of the Carpathian region have been demonstrated. 相似文献
3.
S.B. Lyakhov A.D. Maiorov G.G. Managadze O.A. Povalyaev A.I. Chmil L.Yu. Kochmarev E.G. Shustin M.F. Friedrich W.K. Riedler A.N. Laliashvili A. Kiraga Z. Kłoss Z. Kravchic N.A. Leonov 《Planetary and Space Science》1982,30(4):347-357
Laboratory results of beam plasma discharge (BPD) (dimensions several metres) in a homogeneous atmosphere and a jet of neutral gas are presented. The beam was obtained by an electron gun of the same type as used in rocket experiments.The BPD parameters glow intensity, electromagnetic field and its spectrum, electron density as well as the flux of scattered electrons were measured. In addition, photographs of the BPD were taken. The threshold of BPD ignition was determined as a function of gas pressure and beam parameters. The initial stage of BPD formation as well as various types of oscillatory processes in the discharge were studied. A possible process of BPD initiation is presented. 相似文献
4.
Vo?V.?Anh Philip?Broadbridge Andriy?Olenko Yu?Guang?WangEmail authorView author&#;s OrcID profile 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(9):2585-2603
This paper gives the exact solution in terms of the Karhunen–Loève expansion to a fractional stochastic partial differential equation on the unit sphere \({\mathbb {S}}^{2} \subset {\mathbb {R}}^{3}\) with fractional Brownian motion as driving noise and with random initial condition given by a fractional stochastic Cauchy problem. A numerical approximation to the solution is given by truncating the Karhunen–Loève expansion. We show the convergence rates of the truncation errors in degree and the mean square approximation errors in time. Numerical examples using an isotropic Gaussian random field as initial condition and simulations of evolution of cosmic microwave background are given to illustrate the theoretical results. 相似文献
5.
Geomagnetism and Aeronomy - The paper quantitatively compares the results of calculations of the electron density Ne by the International Reference Ionosphere model IRI-2016 with experimental data... 相似文献
6.
7.
8.
Filipa Tavares Wahren Maria Tarasiuk Andriy Mykhnovych Myron Kit Karl-Heinz Feger Kai Schwärzel 《Environmental Earth Sciences》2012,65(5):1501-1510
Integrated watershed models require spatially differentiated soil information. However, in many regions of the world the limited
availability of soil data hinders an appropriate simulation of hydro-ecological processes. Such circumstances lead to unsupported
statements, poor statistics, misrepresentations, and, ultimately, to bad resource management. The Western Bug catchment in
west Ukraine is an example of such a region. In the former Soviet Union, soil classification primarily focused on soils of
agricultural importance, whereas, forested, urban, industrial, and shallow soil territories were left underrepresented in
the classification and soil maps. Spatially differentiated soil texture data are required to predict soil hydraulic properties
using pedotransfer functions (PTFs), along with soil maps. Furthermore, the Ukrainian soil texture scheme does not match the
particle size classes commonly used with PTFs. To overcome these shortcomings, a fuzzy logic methodology was applied, based
on terrain and vegetation/land use analysis and soil sampling, to close the information gaps. For the application of PTFs,
a procedure was tested to estimate missing values of soil texture distribution. Applied methods were evaluated using recent
soil surveys, measured soil texture, and water retention properties, while having in consideration the limitations brought
by scarce soil data for integrated watershed modelling purposes. 相似文献
9.
The most widespread instrument used today for the measurement of quasi-stationary and slowly fluctuating vector magnetic fields is a flux-gate magnetometer (FGM). The most important parameter characterizing the magnetometer quality is its magnetic noise—its threshold sensitivity or its own noise level (NL). Based on the results of experimental research, we may state that the FGM NL mainly depends on the quality of the magnetic material used for FGM sensor core. The “solid liquid” model explaining the nature of magnetic noise is proposed and substantiated. It is demonstrated that special attention has to be paid to the annealing of the core. A new effect—termed gamma-magnetic normalization—is discovered and discussed. It is shown that the magnetometer NL depends not only on the core length and volume but also on the excitation mode of the core. Besides, the ways to improve other factors, such as power consumption and thermal drift which must be taken into account in order to create a FGM with the highest possible performance, are discussed. Some examples are given of the parameters of present advanced FGMs for geophysical uses. 相似文献
10.
Andriy Gnyp 《Acta Geophysica》2010,58(4):587-603
Three groups of recurrent events have been identified within the 2005–2006 Mukacheve series of about forty M
SH
0.3–1.8 near-surface earthquakes. After a cross-correlation analysis of their waveforms and subsequent relocation with application
of the adjusted arrivals and station terms it turned out that they most likely belong to at least two distinct crustal layers
separated by an interface at about 4 km; the seismic activation started deeper and progressed upwards. As concerns polarities
of first arrivals, the same source mechanism was inferred within individual groups, indicating a normal faulting along the
Az ≈ 120° with a slight component of right lateral slip; this finding is consistent with data available on some other local
sources, as well as with an ambient field of extensional stresses in the local crust and a significant horizontal gradient
of vertical movements across the epicenter area of the Mukacheve series. 相似文献